Acquired Immuno-Deficiency Syndrome (AIDS) and Human Immuno-Deficiency Virus (HIV) in Nevada – Annual Surveillance Report (1999)

摘要

Background:Acquired Immuno-Deficiency Syndrome (AIDS) is the most severe manifestation of Human Immunodeficiency Virus (HIV) infection. AIDS was first reported in the world in 1981 by the Centers for Disease Control and Prevention. Statewide surveillance for AIDS was begun in 1982. Because the cause of AIDS was unknown at that time, the surveillance case definition included many opportunistic infections and tumors. Persons with AIDS were noted to have abnormalities in their immune system that left them susceptible to certain infections. As more information became available, the AIDS surveillance case definition was modified.In 1984, HIV was found to be the cause of AIDS. HIV infects a specific cell of the immune system, the T-lymphocyte, and kills the cell. Very often, HIV infection is without symptoms, and people do not know they are infected. However, they carry the virus in their blood and other body fluids and can infect other persons exposed to these fluids.Persons with unrecognized and untreated HIV infection may not have symptoms for years. The average time from untreated HIV infection to AIDS is 8 to 10 years. Many drugs are now available to treat HIV infection. The usual regimen is a combination of drugs that are taken daily. The goal of treatment is to reduce the amount of virus in the blood to “undetectable” levels by laboratory methods, and to maintain a level of T-lymphocytes that keeps the immune system function intact. When a person with HIV infection stays on an effective treatment regimen they may never reach the AIDS stage. Therefore, AIDS surveillance will not be a true indicator of the burden of HIV disease in our communities.In 1992, Nevada initiated mandatory reporting of HIV infection by name. The purpose was to find persons with early HIV infection and ensure that they were educated about their disease and referred to appropriate treatment. Therefore, Nevada has a surveillance system both for HIV infection and for AIDS. Not all states have HIV surveillance; therefore AIDS cases are used for comparison of relative rates of cases between states.AIDS cases in this report are cases where the person who has HIV has developed the disease called AIDS. HIV cases in this report are cases where the person has the virus called HIV, but has not yet developed the disease called AIDS. Once an HIV case becomes an AIDS case, the AIDS and HIV surveillance system is updated to reflect that occurrence. This report provides the results of both cases and gives definitions for both.